Field of the Invention
The present invention relates to a water saving and energy saving process for the continuous production of whole grain flour and whole gluten-free flour. More particularly, the present invention preconditions the soaked whole-grain with water, and uses an energy efficient blanching treatment with saturated steam during the manufacture of the whole grain and whole gluten-free flour for the preparation of whole grain products and baked foods.
Description of Related Art
Every day, the average person needs to consume enough food to provide around 2,150 dietetic calories or Kcal (9 MJ) of energy. The amount will vary depending on age, size and level of physical activity. Average food availability in low developing countries is below 2,030 calories per day per capita, and about 2,700 in nutrition transition countries. In developed countries, by contrast, it is around 3,750 calories and some of this excess has resulted in high levels of obesity and non-communicable chronic diseases. As populations become more urban and incomes rise, diets high in fat, sugar and animal protein replace more traditional diets that were high in complex carbohydrates and fiber. Ethnic cuisine (e.g., Mediterranean) and unique traditional cereal (amaranth, sorghum, rice, corn, wheat and legume (bean, lentil, chickpea) foods are being replaced by fast foods increasing their energy density. Bread making is one of the most ancient methods of cereal processing. Today, flat breads are still the dominant breads and are either unleavened (corn tortilla and wheat chapati) or leavened by microorganisms (wheat bread) or chemical agents (wheat tortilla). The flour may be prepared from grass seeds (cereal), legume and tubers.
The total energy-related costs as a share of the production cost vary widely for food products. For example, in the United States the energy-related costs as a proportion of the total crop production ranged from about 10% for oilseed soybean to about 31% for cereal corn. At present, renewable energy meets over 13% of global primary energy demand. Almost half of this energy comes from traditional sources of biomass used for cook processing. Process-oriented strategies can reduce the environmental impacts with the design and manufacture of sustainable foods.
Minimal processing technologies in the food industry are designed to limit the impact on nutritional and sensory quality while preserving the food without additives. Hydrothermal treatment, i.e., High-Temperature and Short-Time (HTST), is a milder process intended to partially gelatinize the starch and modify its physical properties without destroying granule structure while improving its stability under shear and heat processing. HTST treatment can be accomplished at low moisture (<35%) even at temperatures above the gelatinization temperature, yielding a harder granule (elastic property) after moist-heat treatment (Jacobs et al. 1998; Sair 1967). The existence of well-defined bimodal particle size distributions has been reported in food systems due to disintegration and aggregation processes having both shattering mechanisms (yielding a larger-size group of particles) and surface erosion mechanisms (yielding a smaller-size group of particles). Dominance of either mechanism is determined by the particle's properties and the physical features of the size reduction apparatus (i.e., the impact mill or attrition mill); the coarser the milling, the larger the size mode and harder the fraction in bimodal distributions (Popplewell et al. 1989; Aguilar et al. 1991).
Blanching is a thermal process where the grain or seed is heated for the purpose of inactivating enzymes, modifying texture (starch and protein), and preserving the color, flavor and nutritional value. Hot water and steam are commonly used heating media, but hot gas (dry-heat) has also been used. Steam infusion heating is a direct-contact process where condensation occurs on the surface of a flowable food, under atmospheric pressure. This process requires atmospheric steam, pumpable food and a mechanical device to facilitate the steam heating and condensation.
The cost for water use and its environmental treatment can affect sustainability in expanding cereal processing plants, particularly in areas where water supply is scarce. Also, low or zero-carbon energy technology with reduced energy-related emissions will contribute to the stabilization of greenhouse gas concentration levels.
Commercial rotary cooker/cooler and screw conveyor systems, using hot-water and steam-injection, have been designed to improve blanched food product quality (e.g., MULTI-TURBULENT® blancher, PPM Technologies Inc., Oregon, USA), energy conservation and waste reduction (Lyco VAPOR FLOW® and Lyco PRESSURE FLOW®; Thomas Conveyor Co, Texas, USA), and those disclosed in U.S. Pat. No. 3,778,521, U.S. Pat. No. 3,910,175, U.S. Pat. No. 5,289,759, U.S. Pat. No. 5,327,817, U.S. Pat. No. 6,263,785, and U.S. Pat. No. 7,348,036, and in EP 1061818 and WO 127922A1.
Although the above described methods can be useful in producing whole flour, an energy saving process for the continuous production of whole grain flour and whole gluten-free flour using preconditioning with water and efficient blanching with saturated steam was still unavailable in the field at the time of the present invention.